The extreme cold in the service of science

Cryogenic Engineering has for a long time been identified as a key technology in the missions of CEA for fundamental research activities. Particle Physics, Astrophysics, Magnetic and Inertial Fusion are fields of Physics which need complex Equipments or Infrastructures (LHC and future upgrade, Tore Supra, JT60-SA, ITER, LMJ, Hiper, Herschel, Planck, and in the future Ixo, Spica and the cryogenic missions in Cosmic Vision 1 and 2), where cryogenics is one of the key issues. In this context, SBT targets to serve the national and international research community by providing expertise, unique prototypes and specifically designed devices building upon the know-how derived from 50 years of cryogenic engineering.

In order to fulfil its general mission and objectives, SBT is technically involved in three major topics: (i) refrigeration, (ii) cryogenic distribution to the end users (detector, superconducting magnet, cryogenic target…) and (iii) development of advanced cryostats.

• The temperature and power ranges are very broad: the temperature range starts from sub Kelvin (< 30 mK) to rather high (140 K) temperatures, and the cooling power lies between extremely low power (µWatt) in the sub Kelvin domain, to huge powers (more than kW) for accelerator and magnetic fusion applications.



• The heat transfer covers a wide area of applications: in large plants a cryodistribution system is necessary, starting from the large refrigerator, to reach the components to be cooled (magnets, cryopumps, detectors). On the other hand, the generalization of cryocoolers at small and intermediate cooling power also leads us to look at the problem of the distribution of cold power to end-users.



• Coming from past activities (physicists at CEA needed high-tech cryostats for their experiments), SBT develops high technology cryostats able to fill, transfer and position the inertial fusion target for the indirect drive approach (LMJ project). The quality of the target is fundamental; and this later is strongly related to the quality of the whole cryogenic chain.